an extension from UIViewController

UIViewControllerExtension.swift

import SJProgressHUD
class UIViewControllerExtension {
  
  extension UIViewController {
      func showWaiting(message: String){
        SJProgressHUD.showWaiting(message)
      }
      func showError(message: String){
        SJProgressHUD.showError(message)
      }
  }

}